1. Field of the Invention
This invention relates to the servicing of underground watering systems, and more particularly concerns a hand tool for the removal and replacement of sprinkler head components of underground systems for lawn watering.
2. Description of the Prior Art
Underground watering systems are commonly utilized for accurately and controllably spraying water onto grass lawns. Such systems are comprised of plastic supply pipes arranged as a substantially horizontal network installed about one to two feet below the lawn. At strategic intervals and locations, riser pipes are vertically emergent from the supply pipes, and terminate in male threaded extremities.
A sprinkler head is attached to the upper extremity of each riser pipe. The sprinkler head is comprised of a cylindrical housing, generally of plastic construction, having a centered bottom female threaded collar aperture adapted to screw onto the threaded upper extremity of the riser pipe. A removable spring-actuated internal cartridge is seated within the cylindrical housing, and is secured therein by external threading on the upper extremity of the housing. The upper extremity of said cartridge has a circular rim having peripheral apertures for the radial distribution of water. Said rim is operationally positioned at an elevation adjacent the root line of the grass.
In the course of foot and/or vehicle traffic upon the lawn, and mowing maintenance, sprinkler heads become damaged, and often require replacement. U.S. Pat. No. 4,788,894 to Mitschele discloses a hand tool for removing sprinkler heads from underground watering systems. Mitschele's tool is comprised of a hollow encasement dimensioned to embrace the entire length of the sprinkler head while also engulfing surrounding soil. The encasement containing the sprinkler head is then twisted, causing the engulfed soil to compressively grip the housing member of the sprinkler head. Further twisting causes the sprinkler head to unthreadably detach from the underlying riser pipe to permit upward removal. Such action leaves an empty hole in the ground.
Although the Mitschele tool may perform properly with permissive soil texture and moisture, removal of the compressed soil from the encasement is difficult. Even more difficult is the return of the removed soil to the hole to facilitate proper seating of a replacement sprinkler head while preventing soil from entering the open upper extremity of the riser pipe. Also, Mitschele makes no provision for accurately aligning a replacement sprinkler head for threadable engagement with the upper extremity of the riser pipe.
Accordingly, it is an object of the present invention to provide a tool for the removal and replacement of a sprinkler head component of an underground watering system.
It is another object of this invention to provide a tool as in the foregoing object which can be hand-manipulated.
It is a further object of the present invention to provide a tool of the aforesaid nature which does not require removal of surrounding soil to achieve removal of a sprinkler head.
It is an additional object of this invention to provide a tool of the aforesaid nature having means for aligning a replacement sprinkler head for proper threaded installation upon an underlying riser pipe.
It is a still further object of the present invention to provide a tool of the aforesaid nature adaptable to use with sprinkler heads of various diameter.
It is yet another object of this invention to provide a tool of the aforesaid nature which is easily maintainable, durably constructed and amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.